This invention relates to a lift device to facilitate raising and lowering a patient transport cot to move a patient into and out of a patient transport vehicle. Patient transport cots are used to carry patients from a first place, such as a place of injury, to an ambulance to be transported to a specified place, such as a medical facility. Upon arrival at the latter place, the cot, with the patient still on it, is removed from the ambulance and guided to a certain location, such as an emergency room, in the specified place. The cot includes a bed portion supported on a collapsible undercarriage that, in turn, is supported on caster-mounted wheels. In addition to these wheels, the cot has front end wheels mounted just below the front end of the bed portion and ahead of the undercarriage.
When a cot is to be loaded into an ambulance, the front end of the cot, including the front end wheels, is rolled a short distance into the ambulance, but not so far as to interfere with folding the undercarriage to a retracted location just below the bed portion. Patient transport personnel controlling movement of the transport cot must then lift the rear end of the cot, so that the undercarriage wheels will be free of any weight on them. To do this, the front end wheels are used as a fulcrum against the floor of the ambulance, and the cot is supported entirely by the front end wheels at one end and transport personnel at the other end while the undercarriage is folded up to its retracted position. The cot, with the patient still on it, can then be pushed fully into the ambulance and anchored to floor-mounted fixtures.
Lifting the rear end of the cot and holding it in midair places a great strain on the transport personnel, depending on the combined weight of the cot, the patient, any medical equipment that must accompany the patient on the cot, and the distribution of all of that weight along the length of the cot. For example, patient transport personnel are sometimes required to lift, either individually or as a team, weights of up to nearly 400 lbs. An 80 lb. patient transport cot with a 200 lb. patient on it requires a single patient transport worker to lift only approximately 150 lbs. at the rear end of a patient transport cot, but a really heavy patient whose weight is closer to the transport cot limit of 650 lbs., could require one member of the patient transport crew to lift approximately 390 lbs. The equipment that accompanies the patient on the cot sometimes includes such things as incubators, IV pumps, compressed gas cylinders, and associated medical devices. While weight capacities of patient transport cots vary with design and may range between 450 lbs. and 650 lbs., bariatric patient transport cots are available for extremely heavy patients whose weight may exceed 800 lbs. The height of the floor of patient transport vehicles, such as ambulances, above street level typically averages between 30″ and 34″ and while the cot and the patient on it are either being placed in the ambulance or taken out of it, the transport personnel will have to support the maximum weight in that region of height.
Lifting such weights to raise the undercarriage wheels of the cot off the ground and support the cot at that level can and does result in injuries to patient transport personnel and may also result in accidental collapse of the patient cot, potentially injuring the patient. Furthermore, the lifting effort of two or more transport personnel may not be optimally correlated, resulting in one of them suddenly having to bear a larger fraction of the weight than was expected.
When the ambulance reaches its target place, either the medical facility or another place, the cot, still carrying the patient, must be removed from the ambulance by a procedure basically the opposite of that used in getting the cot and patient into the ambulance. The cot must be disengaged from the floor-mounted fixtures to allow patient transport personnel to roll the foot end of the cot out to the edge of the floor of the ambulance. One or more patient transport personnel must then support that end of the cot at about that level above the ground so that the cot can be pulled far enough out of the ambulance to allow the undercarriage to be extended to a load-bearing position and locked in place while keeping the head end wheels on the floor of the ambulance. Only then can the transport personnel allow the cot to be lowered the rest of the way so that the undercarriage wheels are on the ground and can support all of the weight.